As illustrated in FIG. 6, this kind of prior art pipe joint 100 is generally equipped with a pipe 102 which has an outward facing flange 101 in the vicinity of its tip end portion, an annular joint body 103 in one side (left side of FIG. 6) inner peripheral part of which the pipe tip end portion fits, and a tubular fixture 105 which covers an outer peripheral part of the joint body 103 and couples the pipe 102 to the joint body 103.
An inward facing flange 106 fronting on the outward facing flange 101 is formed integrally on one end of the tubular fixture 105, and female threads 107 are cut on an inner peripheral surface of the other end of the fixture 105. The female threads 107 are screwed onto male threads 108 cut on an outer peripheral surface of the joint body 103, so that the pipe 102 is coupled to the joint body 103.
In this structure, however, such a method is employed that coupling work is accomplished by screwing the female threads 107 of the fixture 105 onto the male threads 108, so that the structure requires a time and man power for its assembly process and is not suitable for mass production. Further, since the fixture 105 should always be fitted onto the pipe 102, the structure is unfavorable from the standpoint of storage and transportation.
In order to solve the above problem, such a structure is also well known that has an outward facing flange formed in the vicinity of tip end portion of a first pipe, a stopping member mating immovably with a side surface opposite to a tip end of the outward facing flange, a sealing member fitted onto an outer periphery of the tip end portion of the pipe, a second pipe surrounding an outer periphery of the sealing member so as to compress it, a spacer extending integrally from the second pipe and covering an outer periphery of the first pipe with a radial clearance left between them, and a stopping hole formed on an outer periphery of end portion of the spacer; the stopping member being provided with a pressing projection which is so formed as to be deformed elastically in the radial direction and rests in the stopping hole, and the pressing projection having a stopping groove in which an edge- of the stopping hole rests so as to limit an elastic deformation of the pressing projection when the first pipe moves in a direction as leaving from the second pipe. (Japanese Unexamined Utility Model Publication No. 62-181788).
In this structure, however, the spacer and the stopping member are necessary other than the first and second pipes. Therefore, a quantity of parts becomes large to increase manufacturing cost.
An object of the invention is to solve the above-mentioned problem.